The public health problem addressed by this proposal is that inactivity in individuals with chronic disabilities who use a wheelchair results in signifiant and costly secondary complications, such as pressure ulcers, obesity, diabetes, osteoporosis, and cardiovascular comorbidities. We propose an interactive telehealth monitoring and auto-biofeedback system to promote physical activity, pressure relief maneuver performance, and self-management among wheelchair users. In this project we focus on patients with spinal cord injury (SCI) who are at particularly high risk for developing pressure ulcers from sitting too long (31% annual incidence, 85% lifetime incidence). However, the proposed technology is broadly applicable to wheelchair based telehealth. The proposed technology - which attaches to any wheelchair without modification - has three core components: 1) an activity monitoring system (i.e., wheelchair speed, distance travelled, and number of self-propulsions), 2) a pressure relief monitoring system, and 3) a system that provides reminders and feedback regarding the achievement of pressure relief and physical activity goals. Biofeedback will be delivered locally (to the user) via a wheelchair mounted display and remotely (to the clinician) via a secure internet interface. The enabling technologies are innovative sensor systems to monitor wheelchair specific activity patterns but the significant value comes from integrating these novel measurements within biofeedback system that encourages wheelchair users to actively avoid secondary complications of inactivity and allows care providers to identify at risk patients and intervene efficiently. Existing technologies do not compare with the proposed solution. Products exist to monitor wheelchair seat pressure but these products are costly, cumbersome, and not designed for home use. Products exist to monitor wheelchair specific physical activity but these devices cannot distinguish passive from active wheelchair movement. No existing technology combines these measures with auto-biofeedback and telehealth functionality. The team we have assembled for this collaborative project includes engineers, clinicians, and scientists from BioSensics (a privately held biomedical technology development company) and Rancho Los Amigos National Rehabilitation Center (one of the largest comprehensive rehabilitation centers in the United States). In addition, this project benefits from the consultation of a world-renowned expert in physical activity monitoring (Dr. Bijan Najafi, University of Arizona), as well as a leading expert and critical decision maker in SCI care (Dr. Sophia Chun, Chief of SCI, Veterans Health Administration). This team has collaborated successfully on prior projects. The Specific Aims of Phase I are to 1) improve prototyped and pilot tested versions of the proposed system by leveraging existing BioSensics technologies commercialized through prior NIH SBIR awards; 2) validate the measurements of the proposed system using state-of-the-art tools including a high-density pressure mat and camera-based motion capture, and 3) evaluate the efficacy of local biofeedback (to the user via a wheelchair mounted display) during community usage. By demonstrating that biofeedback increases physical activity and achievement of pressure relief will justify further NIH investment in the proposed technology. Within 6 months of the completion of Phase I, we anticipate having a commercially available beta release of the system (BioSensics has successfully brought several products to market in this timeframe). In Phase II we will develop the remote monitoring and telehealth aspects of the proposed system by adding automatic wireless data transfer capabilities (via mobile and Wi-Fi networks) and developing a secure website for remotely accessing activity data and sending telehealth reminders to the wheelchair mounted display.